<!DOCTYPE html>
<html lang="en">
<head>
  <meta charset="UTF-8">
  <title>Title</title>
</head>
<body>
<script>
  const Test=function(){
    console.log('test');
  }
  const test=new Test()
  console.log(test.prototype);  //undefined
  console.log(Test.prototype); //constructor

  console.log(test.__proto__===Test.prototype); //true
  console.log(Test.prototype.__proto__ === Object.prototype); //true
  console.log(Object.prototype.__proto__ === null); //true

  console.log(Test.__proto__.constructor); //Function

</script>
</body>
</html>
